Mobile bridge and method for erecting a bridge

ABSTRACT

A bridge body ( 10 ) and support elements ( 20 ) of a bridge ( 2 ) to be erected are first put in a starting position in which the elements ( 20 ) are moveably associated with the body ( 10 ), and in which the whole of the body ( 10 ) and the elements ( 20 ) is positioned on the ground. The body ( 10 ) and the elements ( 20 ) are subsequently put in a final position in which the body ( 10 ) is at a higher level than ground level, and in which ends ( 22 ) of the elements ( 20 ) are positioned on the ground ( 21 ), by letting a separate device engage with the whole of the body ( 10 ) and the elements ( 20 ), and activating the device for exerting a force on the whole as mentioned in an upward direction, while allowing the elements ( 20 ) to perform a movement with respect to the body ( 10 ).

The invention relates to a method for erecting a bridge, wherein a bridge body and at least two support elements for supporting the bridge body on the ground are provided. Furthermore, the invention relates to a method for bringing down a bridge which has been erected by carrying out the method for erecting a bridge in a preferred mode as will be explained later. Also, the invention relates to a mobile bridge comprising a bridge body and at least two support elements for supporting the bridge body on the ground, which is arranged to be erected by carrying out the method for erecting a bridge.

It is a well-known fact that a bridge is a structure which is suitable to be used in a situation in which it is desired to cross a certain area at an elevated level. For example, a bridge may be positioned such as to connect two banks of a river. According to another option, a bridge may be used for separating two traffic streams in order to avoid complex and/or dangerous situations which could otherwise arise when the traffic streams would be at the same level.

In some situations, there is only a temporary need for a bridge. Especially in such situations, it is advantageous if a process of erecting a bridge requires only a minimum of time and effort. Furthermore, it is advantageous if all components of the bridge can be provided by using only one truck.

Many known methods for erecting a bridge comprise the steps of erecting support elements of the bridge, adjusting the positions of the support elements on the ground so that it is possible to place a bridge body on top of the support elements in a predetermined orientation, which is a horizontal orientation in practical cases, and putting the bridge body in place on the support elements. In case the bridge is suitable to be applied as a pedestrian bridge, the bridge may finally be provided with staircases for connecting the bridge body to the ground.

Other known methods for erecting a bridge involve steps aimed at deploying components of the bridge. For example, U.S. Pat. No. 7,350,254 discloses a bridging unit for use in a bridging apparatus for traversing a bridging zone, the bridging unit including a stowage housing which in use is disposed to one side of the zone, a spanning assembly operatively mounted to the stowage housing for movement between a stowed position and a deployed position in which it at least partially traverses the bridging zone in an elevated position, and deployment means operable to cause movement of the spanning assembly between the stowed and deployed positions. The deployment means are integrated with the various components of the bridging unit, and comprise winches, cables, and gearing mechanisms. Furthermore, extendible means such as a hydraulic cylinder or a viscous damper are used.

All in all, the known methods are complex, wherein a lot of effort is required to realize a correct final position of the bridge in a process of erecting the bridge. The invention provides a method for erecting a bridge which is much less labor-intensive than the known methods. In particular, according to the invention, the bridge body and the support elements of a bridge to be erected are first put in a starting position in which the support elements are moveably associated with the bridge body, and in which the whole of the bridge body and the support elements is positioned on the ground, wherein the bridge body and the support elements are subsequently put in a final position in which the bridge body is at a higher level than ground level, and in which ends of the support elements are positioned on the ground, by providing a separate device, letting the device engage with the whole of the bridge body and the support elements, and activating the device for exerting a force on the whole of the bridge body and the support elements in an upward direction, while allowing the support elements to perform a movement with respect to the bridge body.

When the method according to the invention is applied, the bridge is put to an elevated position by means of a separate device, wherein a final shape of the bridge is obtained as a result of the action performed by the device on a whole of the bridge body and the support elements in a starting position on the ground, due to the fact that the bridge body and the support elements are moveably arranged with respect to each other. As soon as the final position of the bridge body and the support elements has been reached, i.e. as soon as the final shape of the bridge has been realized, the bridge body and the support elements can be fixed with respect to each other, so that the final shape of the bridge can be maintained without a further need for the device to exert a force in an upward direction on the bridge. If desired, it is possible to secure the bridge to the ground by fixing the end of at least one support element which is positioned on the ground to the ground. Also, it is possible to adjust the position of the bridge body with respect to the horizontal by adjusting the position of at least one support element with respect to the ground, wherein any suitable means for doing so may be applied, including ratchet-based means.

The invention also relates to a mobile bridge comprising a bridge body and at least two support elements for supporting the bridge body on the ground, which is arranged to be erected by carrying out the method according to the invention as described in the foregoing, wherein the bridge body and the support elements are adapted to assume various positions with respect to each other, and wherein the support elements are adapted to be moveably associated with the bridge body in a starting position.

In general, it is practical for the bridge body to have an elongated shape. The support elements can be coupled to ends of the bridge body, so that the an area underneath the bridge body is clear from obstacles. In that case, a length of the bridge body is a determining factor in respect of a length of an area that can be bridged. For sake of completeness, it is noted that two or more bridges may be used and coupled to each other in a row-like arrangement if the dimensions of one bridge are insufficient to cross a certain area. In that case, support elements of the bridges will be present in the area, which does not necessary need to constitute a problem. Furthermore, it is noted that the bridge body can be composed of various portions which are coupled to each other, wherein it is possible to adjust the length of the bridge body if so desired. In general, numerous possibilities of the shape of the bridge body exist within the framework of the invention. For example, the bridge body may have a generally U-shaped cross-section, wherein a bottom portion of the U shape serves as a roadway for traffic, and wherein legs of the U shape serve to prevent the traffic from falling off the bridge body in a sideward direction. The roadway may have a planar appearance or may be bent to some extent, for example. Also, the roadway can be straight, but it is also possible for the roadway to be curved. Other options for the shape of the cross-section of the bridge body include a square shape or a rectangular shape, wherein the bridge is covered by a roof portion.

In one possible basic embodiment, the bridge according to the invention comprises a bridge body and two support elements, wherein ends of the support elements are hingeably connected to opposite ends of the bridge body, in such a way that a hinge axis extends substantially perpendicular to a longitudinal axis of the bridge body. In that case, a process of providing the bridge body and the support elements and a process of erecting the bridge can be performed as will be described in the following. In the first place, the bridge body and the support elements are provided by means of a truck. The support elements can be dimensioned such as to fit in a space offered by the bridge body, so that it is possible to have all components loaded in just one truck. Due to the fact that according to the invention, erecting the bridge does not involve erecting the support elements first and then placing the bridge body on top of the support elements, there is no need for the support elements to be as wide as the bridge body, which is often the case in prior art situations, in which it is therefore not possible to have a compact arrangement of the bridge body and the support elements during transport.

When the bridge body and the support elements are unloaded from the truck, the bridge body and the support elements are put in a starting position on the ground. In this position, an end of each of the support elements is hingeably connected to an end of the bridge body, so that a whole of the bridge body and the support elements is obtained in which the support elements are arranged in line with the bridge body, on opposite sides of the bridge body. Subsequently, a hoisting device such as a crane is used for putting the bridge body and the support elements from the starting position to a final position by pulling the whole of the bridge body and the support elements upwards. To this end, the crane is put into engagement with the whole of the bridge body and the support elements, and the crane is operated to put the bridge body to a higher level, wherein the support elements are allowed to perform a movement with respect to the bridge body. In particular, the ends of the support elements which are not connected to the bridge body, i.e. the free ends of the support elements, slide over the ground, while an orientation of the support elements is changed from a more or less horizontal position to a more upright position until the final position has been reached. In this respect, it is advantageous for the free ends of the support elements to be provided with wheels, so that the resistance which is encountered at the positions where the ends contact the ground is minimized.

For sake of completeness, it is noted that it is very practical for the crane to engage with only the bridge body, for example, at a central position of the bridge body. The bridge body may be equipped with an element which is particularly intended to enable the crane to engage with the bridge body in a controlled and safe manner. The crane may be installed on the truck by means of which the bridge body and the support elements are transported to the area where the bridge needs to be erected. Alternatively, it is also possible that a lifting device is used for putting the bridge body and the support elements to the final position, i.e. a device which is adapted to exerting the force which is necessary for getting the bridge body and the associated support elements to a higher level from underneath the whole of the bridge body and the support elements.

When the bridge body and the support elements are in the final position, measures need to be taken for ensuring that the final shape of the bridge is maintained without further assistance from the hoisting or lifting device. This is achieved by fixing the bridge body and the support elements with respect to each other when the final position has been reached. For example, fastening means such as bolts and nuts can be provided and arranged at positions where the bridge body and the support elements contact each other. Applying twist locks is another example of a possibility for fixing the bridge body and the support elements with respect to each other. According to a preferred option, a snap connection is established between the bridge body and the support elements when the final position has been reached, wherein fixing can take place automatically. This can be achieved when both the bridge body and the support elements are provided with elements which are adapted to establish a snap connection between the bridge body and the support elements when the elements are put in contact with each other. In practical cases, the position of the elements for establishing the snap connection is chosen such as to be a position where the bridge body and the support elements contact each other as soon as the final position has been reached. As long as the bridge body and the support elements are not in the final position, the bridge body and the support elements are still moveable with respect to each other. As the bridge body is put to a higher level, the support elements move with respect to the bridge body until the final position is reached and the snap connection is established.

In particular, it may be so that in the starting position, the bridge body is orientated substantially horizontally, and the support elements are orientated substantially horizontally as well, whereas in the final position, the bridge body is still orientated substantially horizontally, and the support elements are orientated at an angle with respect to the horizontal as a result of the fact that a hinging movement of the support elements with respect to the bridge body has taken place. In any case, in the final position, measures can be taken for fixing the bridge to the ground and, if necessary, for adjusting the orientation of the bridge body. It is possible for the bridge to be erected at another place than the location where the bridge finally needs to be, preferably a place which is quite close to that location. In that case, the bridge is displaced to the predetermined location before the possible actions of fixing the bridge to the ground and making final adjustments so that all components of the bridge can be in a proper orientation are taken. An advantage of having a possibility of erecting the bridge at another place than the predetermined location is that a suitable place can be chosen. The advantage is all the more evident when the bridge is intended to be used for crossing a road, as the traffic does not need to be hindered during the process of erecting the bridge.

In respect of the final position of the bridge body and the support elements, it is noted that it is possible that a suitable final position is chosen, dependent on the circumstances. For example, if a bridge with a bridge body at a relatively low level is needed, the final position is reached earlier than if a bridge with a bridge body at a relatively high level is needed. In the first case, the support elements will be in a position which can be denoted as being less folded out with respect to the bridge body than in the latter case.

Many alternatives of the basic embodiment of the bridge as described in the foregoing are feasible within the framework of the invention. For example, the bridge body and the support elements do not necessarily need to be interconnected in a hinging fashion. In this respect, a feasible alternative is a slideable arrangement of the support elements in the bridge body, at opposite sides of the bridge body. In such a case, when the bridge body and the support elements are put from the starting position to the final position, the support elements are allowed to slide with respect to the bridge body while the bridge body is put to a higher level.

For the purpose of allowing access to the bridge body from ground level in the final position of the bridge body and the support elements, it is practical if measures are taken for connecting the ground and the bridge body in a way which is appropriate in this respect, at two ends of the bridge bodies. For example, it may be handy to have staircases at both sides of the bridge, by means of which pedestrians are allowed to access the bridge at one side and to leave the bridge at another side. This may be realized in various ways. In the first place, it is possible that the support elements are formed like stair cases. In such a case, there is no need for providing separate components besides the bridge body and the support elements. Once the bridge is ready, the stair cases carry the entire weight of the bridge body. In the second place, it is possible that staircases are provided as separate components which are adapted to be attached to the bridge. In the third place, the support elements may comprise a portion of staircases, wherein elements which are formed like another portion of the stair cases are provided and attached to the bridge.

The components of the bridge may be made of any suitable material such as steel, aluminum, plastic, wood, etc. The support elements can be steel beams, but, as mentioned in the foregoing, other options exist when it comes to the embodiment of the support elements. Besides the fact that the support elements can be formed as stair cases or can at least comprise a portion of staircases, the support elements can be telescopic elements, in which case the statement that the support elements are movably associated with the bridge body should be understood such as to mean that the support elements are extendable and retractable with respect to the bridge body, the support elements can comprise an air bag, the support elements can be adapted for serving as pneumatic or hydraulic supports, or the support elements can be formed like supports which are to be filled with water or air, to mention a few examples.

In case the bridge comprises staircases, the bridge may furthermore be equipped with elements, for example, gutter-like elements, which allow cyclists to cross the bridge with their bicycles. According to another option, an automated system for transporting bicycles along the bridge may be used. It is also possible that the staircases are omitted, and that the support elements extend at an angle with respect to the horizontal which allows for cyclists to cycle across the bridge. Furthermore, the bridge may have arrangements on the basis of which elevators can be used with the bridge, so that the bridge may also be accessible to persons in a wheelchair, parents with a child in a stroller, etc.

All in all, when compared to known bridges, the bridge according to the invention can be erected in a simple and fast manner, so that costs can be saved. It is possible to transport the components of the bridge by means of only one truck, wherein two persons can perform the whole operation of erecting the bridge with the help of a crane or the like, preferably a crane which is present on the truck. Hence, another advantage of the invention is that harm to the environment can be minimized. The bridge according to the invention may be relatively light, yet stable, and can be easily erected at one place and subsequently displaced to a predetermined location as mentioned earlier.

The invention also relates to a method for bringing down a bridge which has been erected by carrying out the method as described in the foregoing, in a mode in which a snap connection is established between the bridge body and the support elements when the final position has been reached, wherein the snap connection as mentioned is released by exerting a force on the whole of the bridge body and the support elements in an upward direction. In general, snap connections can be of such a nature that both establishing and releasing the connection are achieved by exerting pressure for moving one element beyond another, wherein coupling or decoupling of the elements is obtained, dependent on a starting condition. When such a type of snap connection is applied in the bridge according to the invention, the connection between the bridge body and the support elements can be released by bringing the bridge body to a somewhat higher level. As soon as the connection has been released, the bridge body and the support elements are capable of moving with respect to each other again, so that it is possible to put the bridge body and the support elements back to the starting position and disassemble the bridge. This is a very efficient manner of bringing down a bridge, wherein there is no need for labor-intensive actions such as removing fastening means etc.

The invention will be explained in more detail on the basis of the following description of two embodiments of a bridge according to the invention and a method for erecting the bridge. Reference will be made to the drawing, in which equal reference numerals indicate equal or similar parts, and in which:

FIGS. 1, 2 and 3 shows different views of a first embodiment of the bridge according to the invention;

FIG. 4 shows an end portion of a bridge body of the bridge and a support element connected to an end of the bridge body;

FIG. 5 shows the end portion of the bridge body and the support element as shown in FIG. 4, as well as a portion of a staircase as attached to the bridge; and

FIGS. 6, 7 and 8 shows different views of a second embodiment of the bridge according to the invention.

FIGS. 1, 2 and 3 shows different views of a first embodiment of a bridge 1 according to the invention, which comprises an elongated bridge body 10 and four support elements 20. In the figures, a final shape of the bridge 1 is shown, in which the bridge body 10 has an elevated position with respect to the ground 21, and in which ends 22 of the support elements 20 are positioned on the ground 21. Two support elements 20 are arranged at every end 11, 12 of the bridge body 10, wherein the support elements 20 extend in two different sideward directions, i.e. in directions substantially perpendicular to a longitudinal axis 13 of the bridge body 10, which is a substantially straight axis in the shown example. In this way, the bridge 1 is supported on the ground 21 in a stable manner.

The bridge body 10 has a bottom portion 14 which is suitable to serve as a roadway for persons and/or vehicles crossing the bridge, possibly in combination with a suitable cover layer. Apart from that, the bridge body 10 can be designed in any suitable manner, wherein it is preferred to have a lightweight construction having sufficient stiffness, and wherein it is preferred for the bridge body 10 to comprise standing side walls 15 which can be at least partially closed for preventing persons and/or vehicles crossing the bridge 1 from falling from the bridge 1.

The bridge 1 as shown in FIGS. 1, 2 and 3 has been erected by starting from a position in which the bridge body 10 had a position on the ground 21, and in which the support elements 20 were only hingeably connected to the bridge body at hinging areas 16, at a top side of the side walls 14 of the bridge body 10, and were partially supported on the ground 21 as well. For example, the bridge body 10 may be equipped with shafts (not shown), and the support elements 20 may be equipped with hooks (not shown) for engaging with the shafts, such that the hooks can be rotated about the shafts, which does not alter the fact that other options exist within the framework of the invention. For sake of completeness, it is noted that the hinge axes between the bridge body 10 and the support elements 20 extend substantially parallel to the longitudinal axis 13 of the bridge body 10.

With the bridge body 10 and the support elements 20 in the starting position as described in the foregoing, a device for exerting an upwardly directed force on the whole of the bridge body 10 and the support elements 20 was made to engage with the whole as mentioned. As soon as the device was operated, the bridge body 10 was moved off the ground 21 to a higher level. In the process, due to the hinging nature of the connection between the bridge body 10 and the support elements 20, the position of the support elements 20 with respect to the bridge body 10 and with respect to the ground 21 changed. In particular, an orientation of the support elements 20 and a position of the ends 22 of the support elements 20 on the ground 21 changed. The ends 22 of a pair of support elements 20 as present at an end 11, 12 of the bridge body 10 moved towards each other until the final position was reached. In FIG. 2, the directions of movement are indicated by means of arrows. In the final position, the bridge body 10 and the support elements 20 were fixed with respect to each other in a suitable way, whether automatically upon reaching the final position, or not. In the shown example, in the final position, the support elements 20 contact the side walls 14 of the bridge body 10 along the entire height of the bridge body 10, which contributes to the stability of the bridge 1. Furthermore, on the basis of this fact, an area where fixation can be realized is sufficiently large for the fixation to be robust en reliable.

In order to compensate for unevenness of the ground 21, the bridge 1 comprises suitable means (not shown) for adjusting the positions of the support elements 20 on the ground, so that a predetermined orientation of the bridge body 10, which may be a horizontal orientation, can actually be realized. Preferably, each support element 20 has a support plate at its end 22, so that the support plates move along with the ends 22 of the support elements 20 over the ground during the process of erecting the bridge 1.

For providing access to the bridge body 10 in the final position, the bridge 1 comprises staircases 30 which are associated with every support element 20. In principle, it is sufficient to have one staircase 30 per end 11, 12 of the bridge body 10. FIGS. 4 and 5 show enlarged views of the a support element 20. In FIG. 4, it can be seen what the support element 20 looks like when the associated staircase 30 is absent, whereas in FIG. 5, a combination of the support element 20 and the staircase 30 is shown. The support element 20 comprises a support beam 23 and an arrangement which is actually a banister 31 of the staircase 30, wherein the support beam 23 and the banister 31 are arranged according to an X. When the bridge 1 is in the final position after a process of erecting the bridge 1 has taken place, the staircase 30 is completed by providing a whole of a stairs portion 32 and another banister 31 and coupling the whole to the bridge body 10 and the support element 20, particularly the banister 31 which is part of the support element 20.

When the positions of the support elements 20 are adjusted in order to have a correct orientation of the bridge body 10, it may happen that a gap is obtained between a bottom step of a staircase 30 and the ground 21 which is too large. Separate steps (not shown) may be used in combination with the bridge 1, so that one or more steps can be coupled to the staircase 30 in such a situation.

At the positions where the staircases 30 end at the bridge body 10, the bridge body 10 is open, so that access to and from the bridge body 10 by means of the staircases 30 is actually possible.

FIGS. 6, 7 and 8 shows different views of a second embodiment of a bridge 2 according to the invention. An important difference between the second bridge 2 and the first bridge 1 resides in the positioning of the support elements 20 with respect to the bridge body 10. The fact is that in the second bridge 2, the support elements 20 do not extend in sideward direction with respect to the bridge body 10, but extend in a forward and backward direction with respect to the bridge body 10 instead. The second bridge 2 comprises the same components as the first bridge 1, but these components are assembled in another way.

In the second bridge 2, at each end 11, 12 of the bridge body 10, two combinations of support elements 20 and staircases 30 extend between the bridge body 10 and the ground 21 in a side-by-side configuration. During the process of erecting the bridge 2, the ends 22 of the support elements 20 at different ends 11, 12 move towards each other. In FIG. 6, the directions of movement are indicated by means of arrows.

In the starting position of the second bridge 2, the bridge body 10 and the support elements 20 extend on the ground in the same direction, wherein the support elements 20 are in line with the bridge body 10, at the two ends 11, 12 of the bridge body 10. In the first bridge 1, a person needs to move around the corner when stepping from a staircase 30 to the bridge body 10, and vice versa. In the second bridge 2, a person can move straight on, in the same direction. Openings in the side walls 14 of the bridge body 10 need to be at another position. It may be so that the bridge body 10 is equipped with doors 17 which are hingeably connected to the side walls 15 through a hinge (not shown) which allows for one position of the doors 17 in the bridge body 10 or another, dependent on the positioning of the support elements 20, simply by turning over the hinge.

In FIGS. 7 and 8, it can be seen that in the side-by-side configuration of the two support elements 20 and the staircases 30, two adjoining banisters 31 are present at a central position. It is possible for the banisters 31 to be coupled to the stairs portions 32 in a releasable manner, so that the banisters 31 can be removed if so desired.

It will be clear to a person skilled in the art that the scope of the invention is not limited to the examples discussed in the foregoing, but that several variations and modifications thereof are possible without deviating from the scope of the invention as defined in the attached claims.

In the starting position of a bridge 2 in which the support elements 20 are hingeably connected to the bridge body 10, in a longitudinal orientation, the support elements 20 can be laid on the ground outside of the area where the bridge body 10 is. However, it is also possible to have the support elements 20 in a position at a bottom side of the bridge body 10 in the starting position, so that the support elements 20 come from under the bridge body 10 when the bridge body 10 is put to a higher level while performing a hinging movement with respect to the bridge body 10, wherein ends 22 of the support elements 20 for touching the ground move apart.

The number of support elements 20 can be four as is the case in the examples shown in the figures. However, it is also possible that another number of elements 20 is applied in the bridge 1, 2 according to the invention. It follows from the examples as mentioned that various orientations of the support elements 20 with respect to the bridge body 10 can be chosen, including a transverse orientation and a longitudinal orientation as illustrated by means of the figures.

Practical values of a length of the bridge body 10 are values in a range of 10 to 15 meters, which does not alter the fact that other values are possible within the framework of the invention. A distance of the bottom portion 14 of the bridge body 10 to the ground 21 may be as much as 4 meters, for example. The second bridge 2, i.e. the bridge 2 having the longitudinal configuration, can span a distance of more than 20 meters.

If two or more bridges 1, 2 are positioned in a row, it may be so that the orientation of the support elements 20 which are present at the ends of the row can be freely chosen, whereas the orientation of intermediate support elements 20 is preferably a transverse orientation.

The bridge 1, 2 can be equipped with any suitable systems as desired, such as a lighting system, screens for displaying advertisements or other images and movies at the inside and/or the outside of the bridge 1, 2, etc. 

1. Method for erecting a bridge (1, 2), wherein a bridge body (10) and at least two support elements (20) for supporting the bridge body (10) on the ground (21) are provided, wherein the bridge body (10) and the support elements (20) are first put in a starting position in which the support elements (20) are moveably associated with the bridge body (10), and in which the whole of the bridge body (10) and the support elements (20) is positioned on the ground (21), and wherein the bridge body (10) and the support elements (20) are subsequently put in a final position in which the bridge body (10) is at a higher level than ground level, and in which ends (22) of the support elements (20) are positioned on the ground (21), by providing a separate device, letting the device engage with the whole of the bridge body (10) and the support elements (20), and activating the device for exerting a force on the whole of the bridge body (10) and the support elements (20) in an upward direction, while allowing the support elements (20) to perform a movement with respect to the bridge body (10).
 2. Method according to claim 1, wherein, in the starting position, the support elements (20) are hingeably connected to opposite sides of the bridge body (10), and wherein the support elements (20) are allowed to perform a hinging movement with respect to the bridge body (10) when the bridge body (10) and the support elements (20) are put in the final position.
 3. Method according to claim 2, wherein, in the starting position, the bridge body (10) and the support elements (20) are hingeably connected to each other through assemblies of a hook and a shaft engaged by the hook, in which the hook and the shaft are rotatable with respect to each other.
 4. Method according to claim 2, wherein the ends (22) of the support elements (20) which are positioned on the ground (21) in the final position are provided with wheels, and wherein the wheels as mentioned are allowed to roll over the ground (21) when the support elements (20) perform a hinging movement with respect to the bridge body (10) as the whole of the bridge body (10) and the support elements (20) is put from the starting position to the final position.
 5. Method according to claim 1, wherein, in the starting position, the support elements (20) are slideably arranged in the bridge body (10), at opposite sides of the bridge body (10), and wherein the support elements (20) are allowed to perform a sliding movement with respect to the bridge body (10) when the bridge body (10) and the support elements (20) are put in the final position.
 6. Method according to claim 1, wherein the separate device is activated for exerting a pulling force on the whole of the bridge body (10) and the support elements (20) in an upward direction.
 7. Method according to claim 1, wherein the bridge body (10) and the support elements (20) are fixed with respect to each other when the final position has been reached.
 8. Method according to claim 7, wherein a snap connection is established between the bridge body (10) and the support elements (20) when the final position has been reached.
 9. Method according to claim 7, wherein fastening means are provided, and wherein the fastening means are arranged at positions where the bridge body (10) and the support elements (20) contact each other.
 10. Method according to claim 1, wherein the separate device which is applied for exerting the force on the whole of the bridge body (10) and the support elements (20) in an upward direction is a hoisting device.
 11. Method according to claim 1, wherein the bridge body (10) and the support elements (20) are provided by means of a truck comprising a crane, and wherein the crane as mentioned is applied for exerting the force which is used for putting the bridge body (10) and the support elements (20) from the starting position to the final position.
 12. Method according to claim 1, wherein the separate device which is applied for exerting the force on the whole of the bridge body (10) and the support elements (20) in an upward direction is a lifting device.
 13. Method according to claim 1, wherein the support elements (20) are provided in the form of stair cases (30).
 14. Method according to claim 1, wherein staircases (30) are provided and attached to the whole of the bridge body (10) and the support elements (20) when the final position has been reached.
 15. Method according to claim 1, wherein the support elements (20) comprise a portion (31) of staircases (30), and wherein another portion (31, 32) of the staircases (30) is provided and attached to the whole of the bridge body (10) and the support elements (20) when the final position has been reached.
 16. Method according to claim 1, wherein the bridge body (10) and the support elements (20) are provided by means of a truck, and wherein, in the truck, the support elements (20) are stored in a space offered by the bridge body (10).
 17. Method according to claim 1, wherein, in the final position, the end (22) of at least one support element (20) which is positioned on the ground (21) is fixed to the ground (21).
 18. Method according to claim 1, wherein, in the final position, the position of the bridge body (10) with respect to the horizontal is adjusted by adjusting the position of at least one support element (20) with respect to the ground (21).
 19. Method for bringing down a bridge (1, 2) which has been erected by carrying out the method according to claim 8, wherein the snap connection between the bridge body (10) and the support elements (20) is released by exerting a force on the whole of the bridge body (10) and the support elements (20) in an upward direction.
 20. Mobile bridge (1, 2) comprising a bridge body (10) and at least two support elements (20) for supporting the bridge body (10) on the ground, which is arranged to be erected by carrying out the method according to claim 1, wherein the bridge body (10) and the support elements (20) are adapted to assume various positions with respect to each other, and wherein the support elements (20) are adapted to be movably associated with the bridge body (10) in a starting position.
 21. Mobile bridge (1, 2) according to claim 20, wherein the bridge body (10) and the support elements (20) are adapted to be hingeably connected to each other, at opposite sides of the bridge body (10).
 22. Mobile bridge (1, 2) according to claim 21, wherein one of the bridge body (10) and the support elements (20) comprises a shaft, and wherein another of the bridge body (10) and the support elements (20) comprises a hook for engaging with the shaft.
 23. Mobile bridge (1, 2) according to claim 21, wherein ends (22) of the support elements (20) are provided with wheels.
 24. Mobile bridge (1, 2) according to claim 20, wherein the support elements (20) are adapted to be slideably arranged in the bridge body (10), at opposite sides of the bridge body (10).
 25. Mobile bridge (1, 2) according to claim 20, comprising at least one element which is suitable for allowing a separate device to engage with the bridge (1, 2) and to exert a force on the bridge (1, 2) in an upward direction.
 26. Mobile bridge (1, 2) according to claim 20, wherein both the bridge body (10) and the support elements (20) are provided with elements which are adapted to establish a snap connection between the bridge body (10) and the support elements (20) when the elements are put in contact with each other.
 27. Mobile bridge (1, 2) according to claim 20, wherein the support elements (20) are formed like stair cases (30).
 28. Mobile bridge (1, 2) according to claim 20, further comprising at least two staircases (30) which are adapted to be attached to the bridge (1, 2).
 29. Mobile bridge (1, 2) according to claim 20, wherein the support elements (20) comprise a portion (31) of staircases (30), and wherein the bridge (1, 2) further comprises at least two elements which are formed like another portion (31, 32) of the staircases (30), and which are adapted to be attached to the bridge (1, 2).
 30. Mobile bridge (1, 2) according to claim 20, wherein the support elements (20) fit in a space offered by the bridge body (10) for the purpose of transport of the bridge (1, 2). 